84 research outputs found
Method for orthorectification of terrestrial radar maps
International audienceThe vehicle-based PELICAN radar system is used in the context of mobile mapping. The R-SLAM algorithm allows simultaneous retrieval of the vehicle trajectory and of the map of the environment. As the purpose of PELICAN is to provide a means for gathering spatial information, the impact of distortion caused by the topography is not negligible. This article proposes an orthorectification process to correct panoramic radar images and the consequent R-SLAM trajectory and radar map. The a priori knowledge of the area topography is provided by a digital elevation model. By applying the method to the data obtained from a path with large variations in altitude it is shown that the corrected panoramic radar images are contracted by the orthorectification process. The efficiency of the orthorectification process is assessed firstly by comparing R-SLAM trajectories to a GPS trajectory and secondly by comparing the position of Ground Control Points on the radar map with their GPS position. The RMS positioning error moves from 5.56 m for the raw radar map to 0.75 m for the orthorectified radar map
Relevance of Lipid-Based Products in the Management of Dry Eye Disease
Components of the ocular surface synergistically contribute to maintaining and protecting a smooth refractive layer to facilitate the optimal transmission of light. At the air-water interface, the tear film lipid layer (TFLL), a mixture of lipids and proteins, plays a key role in tear surface tension and is important for the physiological hydration of the ocular surface and for ocular homeostasis. Alterations in tear fluid rheology, differences in lipid composition, or downregulation of specific tear proteins are found in most types of ocular surface disease, including dry eye disease (DED). Artificial tears have long been a first line of treatment in DED and aim to replace or supplement tears. More recently, lipid-containing eye drops have been developed to more closely mimic the combination of aqueous and lipid layers of the TFLL. Over the last 2 decades, our understanding of the nature and importance of lipids in the tear film in health and disease has increased substantially. The aim of this article is to provide a brief overview of our current understanding of tear film properties and review the effectiveness of lipid-based products in the treatment of DED. Liposome lid sprays, emulsion eye drops, and other lipid-containing formulations are discussed.Peer reviewe
Chronic pneumonia with Pseudomonas aeruginosa and impaired alveolar fluid clearance
BACKGROUND: While the functional consequences of acute pulmonary infections are widely documented, few studies focused on chronic pneumonia. We evaluated the consequences of chronic Pseudomonas lung infection on alveolar function. METHODS: P. aeruginosa, included in agar beads, was instilled intratracheally in Sprague Dawley rats. Analysis was performed from day 2 to 21, a control group received only sterile agar beads. Alveolar-capillary barrier permeability, lung liquid clearance (LLC) and distal alveolar fluid clearance (DAFC) were measured using a vascular ((131)I-Albumin) and an alveolar tracer ((125)I-Albumin). RESULTS: The increase in permeability and LLC peaked on the second day, to return to baseline on the fifth. DAFC increased independently of TNF-α or endogenous catecholamine production. Despite the persistence of the pathogen within the alveoli, DAFC returned to baseline on the 5(th )day. Stimulation with terbutaline failed to increase DAFC. Eradication of the pathogen with ceftazidime did not restore DAFC response. CONCLUSIONS: From these results, we observe an adequate initial alveolar response to increased permeability with an increase of DAFC. However, DAFC increase does not persist after the 5(th )day and remains unresponsive to stimulation. This impairment of DAFC may partly explain the higher susceptibility of chronically infected patients to subsequent lung injury
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Bone Morphogenetic Proteins (BMPs): nouveaux modulateurs de la synthÚse et de la libération de l'hormone folliculo- stimulante (FSH)
Reproductive function requires the secretion of the gonadotropins, luteinizing
hormone (LH) and follicle -stimulating hormone (FSH) synthesized by the gonadotrope cells.
A tight control of the production of these hormones is crucial, particularly in females, to
coordinate the terminal follicular growth, the follicle selection as well as the timing and the
number of ovulation. Synthesis and release of both gonadotropins are controlled by
hypothalamic gonadotropin releasing hormone (GnRH) and gonadal steroids (progesterone
and oestradiol). Despite these common regulators, divergences in the circulating patterns of
LH and FSH are often encountered. Such divergences have suggested that other factors are
specifically implicated in the control of FSH production. Inhibins and activins, members of
the Transforming Growth Factor -Beta (TGF -(3) superfamily, inhibit and stimulate respectively
FSH synthesis and release. These gonadal factors are also produced in the pituitary where
they act as paracrine factors. Other molecules of the TGF -13 superfamily, the Bone
Morphogenetic Proteins (BMPs) have recently been involved for their action in reproduction
at ovary level. Whether BMPs act at pituitary level and participate with other factors to
regulate FSH production in females is not elucidated. In order to extend our knowledge of the
differential regulation of FSH and LH synthesis, this question was addressed in this study and
developed around three purposes:ped around three purposes: - Are BMPs and receptors expressed in pituitary? What are their effects on
gonadotropin production? Does the natural mutation of BMPR -IB in ewes have an effect at
pituitary level?- What are the mechanisms of BMPs action at intracellular level?- Is the mouse gonadotrope cell line LÎTâ a good model to analyse BMP action on
FSH production?Answering to these questions should help to better understand the mechanisms which
control the fertility in females.Before presenting the results, some data concerning the gonadotropins and the
differential control of their synthesis and release are developed followed by a focus on BMP
effects on reproduction. The mechanisms of action of BMPs, as well as activin are also
detailed
Bone Morphogenetic Proteins (BMPs) (nouveaux modulateurs de la synthÚse et de la libération de l'hormone folliculo-stimulante (FSH))
TOURS-BU Sciences Pharmacie (372612104) / SudocSudocFranceUnited KingdomFRG
Mobile Robot Localization and Mapping in Extensive Outdoor Environment based on Radar Sensor - First Results
International audienceWe present in this paper a new microwave sensor developed for autonomous vehicle navigation and perception in extensive outdoor environments. Radar offers advantages as a robotic perception modality, because it is not vulnerable to the functioning conditions found in natural outdoor environments: dust, rain, fog, snow, light conditions, wind turbulences, etc. The developed radar is based on Frequency Modulated Continuous Wave (FMCW) technology, that is well intended for short and medium-range applications. The paper describes the spatial integration that is used in order to reduce the speckle effect in radar image. This anti-speckle filtering is obtained through a dead reckoning phase, using two proprioceptive sensors (odometer and compass heading). The radar sensor is used to develop a Simultaneous Localization And Mapping (SLAM) application. In order to fit the needs of radar image analysis complexity, the SLAM process is purely radar based. This process makes no landmark assumptions, and avoids the data association problem by storing a detailed map instead of sparse landmarks
Methods for FMCW radar map georeferencing
International audienceIn a context of mobile environment mapping, a vehicle-based radar system, K2Pi, has been developed. A mapping of the environment is carried out from the radar datasets. Given the specificities of radar maps, the main problem at this stage is to find a method to georeference these maps. This article proposes three radar map georeferencing methods. The first method is a typical manual selection of a set of control point pairs. The second method consists of matching the relative trajectory computed by a specific radar algorithm with a trajectory recorded from absolute DGPS recording. Finally, the third method, inspired by the image-to-image approach, is based on Fourier-Mellin transform which automatically registers the radar map with respect to a georeferenced aerial photograph. Successfully tested on radar datasets, this method could be applied to many other types of data
Evidence of colloidal transport of PAHs during column experiments run with contaminated soil samples
International audienceBrownfield soils may contain high levels of organic pollutants particularly polycyclic aromatic hydrocarbons (PAHs). It is essential to predict their migration and fate and to evaluate the risk of transfer to sensitive targets, such as water resources, ecosystems and human health. In this study, soil samples have been taken from an experimental contaminated site of former steel activities located at Homecourt (Lorraine, France). These samples have been lixiviated in laboratory column in water-saturated condition at room temperature. The effluent has been collected by fraction and analysed by a standard method giving total concentration of each of 16 PAHs. The breakthrough curves of 16 PAHs significantly evolve in the same way according to the volume of effluent and tend to vanish to 12â15 pore volumes. If several PAHs remain at a concentration below the solubility, others clearly exceed this threshold. Material balance sheets show that only a very small fraction of PAHs is mobilised. These results are interpreted by postulating that PAHs are transported by the solution not only in the dissolved state but also by associations with particulate or dissolved organic matte
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